A piezoelectric component is composed, for example, of a piezo ceramic layer that has both sides provided with a metallic electrode layer. When a different electrical voltage is applied to these electrode layers, then the piezo ceramic layer reacts with a lattice distortion. As a result thereof, the component expands and contracts in a direction that is defined by the arrangement of the piezo ceramic layer and of electrode layers.
DE 196 15 694 discloses a piezoelectric component in the form of a piezo actuator in monolithic multilayer structure. The piezo actuator comprises a stack of alternating electrodes and piezo ceramic layers. One electrode layer serves each neighboring piezo ceramic layer as electrode. To that end, an electrical contacting of the electrode layers ensues in an alternating polarity. The alternating polarity is achieved with the assistance of two metalization strips that are laterally applied to the stack. One metalization strip extends over a height that derives from piezoelectrically active layers of the stack stacked on top of one another. The stack has a quadratic base area. The electrical contacting of the electrode layers ensues at opposite comers of the stack. The spacing from electrode to electrode of different polarity amounts to approximately 80 .mu.m. One of the metalization strips is electrically conductively connected to each second eletrode layer and is insulated from each first electrode layer lying there between. By contrast thereto, the second metalization strip is insulated from every second electrode layer and is electrically conductively connected to each first electrode layer. An insulation of an electrode layer relative to a metalization is achieved in that the electrode layer comprises a recess in a region in which the metalization is applied. The piezo actuator is piezoelectrically inactive in this region since no lattice distortion can be produced here by applying a voltage.
It is important for the functionability of the described piezo actuator that each electrode layer is electrically contacted in the piezoelectrically inactive region. At the same time, it is important that an electrical arc-over or a short-circuit is avoided in a piezoelectrically active area. A lattice distortion occurs in the piezoelectrically active area by applying a voltage. An arc-over can occur between neighboring electrode layers or an electrode layer and an arbitrary electrode of the piezo actuator. A short-circuit can be produced, for example, by mechanical damage, contamination and an influence of atmospheric humidity and/or a fuel (diesel, oil, etc.).